struct S { int X, Y; };

int foo(struct S *P1, struct S *P2, int C) {
  struct S *P;
  if (C) {
    P1->X = 4;
    P1->Y = 2;
    P = P1;
  } else {
    P2->X = 24;
    P2->Y = 2;
    P = P2;
  }
  return P->X + P->Y;
} 
